Motion picture stereoscopy



June 23, 1936. A. w. CARPENTER MOTION PICTURE STEREOSCOPY.

Filed Sept. 25, 1935 INVENTOR r/rfiwr Kai denier ATTORN EY Patented June 23, 1936 UNITED STATES PATENT OFFICE MOTION PICTURE STEBEOSCOPY Arthur W. Carpenter, New York, N. Y., asslgnor to United Research Corporation, Long Island City. N. Y., a corporation of Delaware Application September 25, 1933, Serial No. 690,829 2 Claims. (01. ass-10.6)

The invention relates'to method and means for producing a motion picture stereogram,

In my co pending application Serial No. 688,794 filed September 9, 1933 I have disclosed and claimed certain features important to the production of stereograms on film. I have also disclosed and claimed the adaptation of those features to the production of motion picture stereograms in my co-pending application Serial No. 690,830 filed September 25, 1933 wherein is disclosed an array of plane station mirrors forming-images oi the object from discrete viewpoints with means for sequentially impressing those images on a motion picture film. This sequential operation involves the motion at a rapid speed 01' certain optical apparatus.

The present invention while retaining the important features oi? the first mentioned application, is in the nature 01' an improvement on the second mentioned application in that I dispense with rapidly moving optical parts and provide a stationary optical arrangement for producing at a motion picture speed successive stereograms of a moving object.

For further details of the invention reference may be made in the drawing herein.

Fig. l is a schematic plane view of an arrangement for photographically producing motion picture stereogram.

Fig. 2 is a sectional view of a segmental lens giving equal amounts of light in each segmented area.

Figs. 3, 4, and 5 are sectional views of different types of lineaters whichmay be employed.

Referring in detail to Fig. 1, the object 0, of which a motion picture stereogram is to be photo'- graphically producedon the motion picture film F, is arranged in front an arcuate array of plane station mirrors, S-l, 8-2, S-3, Sl. The base line on which the mirrors, S-l etc. are arranged may be the arc of a circle, or preferably the symmetric portion 01' an ellipse or other conic as disclosed and claimed in my application Seral No. 690,830 filed September 25, 1933. Each of the station mirrors S-l, etc. views the object 0 from a discrete viewpoint. The lines oi. sight from the station mirrors S-l, etc. are brought to a distributor or assembly mirror D, which reflects all of these lines of sight simultaneously to the objective lens P. At or near the image plane 0! lens P is lineater A which may take various forms such as the forms shown in Figs. 3, 4, and 5. The discrete angular views of object 0 as lineated by the lineater A are relayed to the film F by the relay lens R. The film F is 01 course contained in and operated by a standard motion picture camera and as all of the optical parts indicated in Fig. 1 are stationary, a motion picture stereogram oi. moving object 0 may readily be photographed on film F.

In case the film F is 35 m. m. film the lineater A preferably has a total number of lines such as to produce on film F about 420 lines, that is 420 groups of picture elements. For film of any other size, preferably the film should have between 300 10 and 600 lines per inch. Also each picture line element should be of the order of, or at least equal to five silver grains of the emulsion in width and furthermore the number oi viewing stations (Si 3-2, etc.) should be equal to the line pitch of lineater A divided by the width of an elemental line of light passing therethrough. In the case of an opaque screen this ratio comprises the ratio of line pitch to the opening in the screen. As there is no, relative motion of the optical elements in Fig. 1 during the photographic process, the stereogram contains stripes as distingiushed from smears, as disclosed and claimed in my copending applications, Ser. No. 688,794 filed September 9, 1933 and Ser. No. 690,830 filed Septemher 25, 1933.

Because of the recent advances in the design and construction of photographic objectives there have been for the past year available on the mar-v ket objectives of extremely wide aperture with working apertures as high as F 1.4, or even greater. Such an objective, as indicated at P. is anastigmatic and enjoys a high degree of zonal correction. It, therefore, becomes possible to create sufiiciently high grade images using only a segment of the available lens. Such segmental images may be created by the use of segmentally apertured diaphragms as has been suggested in connection with certain color processes. They may equally well be created by one or the mech- 0 anisms which is the subject of this invention. namely, the interposition before the lens P of strips DI, D2, D3, D4 of plane parallel reflecting surfaces disposed at different angles to the axis of the object 0 and at different azimuths within the field of view of the lens P. The strips DI, D2, D3, D4 simultaneously refiect to lens P, the object images in the station mirrors SI, S2, S3, S4 respectively.

If the horizontal angles subtended by these refiectors DI, D2, D3, D4 within the field of view of the lens P are properly proportioned. the active area of each can'be made equal, one with another, and the amount 01 light which goes into the formation of each image will be equal in each directed from the objective P to each of deflecting surfaces Di, D2, D3, D6 difiers in case. Such a condition isindicated in Fig. 2, which is a diagram of the field of view of the lens JP showing four distributorreflectors Di, D2, D3, Dd so proportioned as to yield equal areas of light reflecting surface.

With such amultiple deflector D placed before such an objective P the image formed will consist-of a number of superimposed images; one being formed for each segment of the deflector. Each oi these images will be a complete image oi that portion of the field of view embraced by the individual reflecting surface and ii the deflector D is reinforced as shown by a battery of properly oriented station mirrors Si, as, S3, S -i then these several superimposed images will all be images of the object identical save as respects angle oi view. Since, however, the line of sight these azimuth from its fellows the several resulting images will each be formed by bundles or pen oils of rays, each having a different inherent azininth or inclination to the image surface than that of the bundles of rays forming the other images.

This inherent difierence in orientation of the light forming the different images may be so analyzed by a lineater such as transparent ribbed screen having its retracting ribs arranged paral lei to the long axis of the deflection mirrors Di, D2, D3, D5 as to form the desired types of interlined stereopanoramagrams. Ribbed screens which are suitable to resolve images of this sort are indicated by the sectional diagrams in Figs. 3, i, and 5. if a ribbed analyzer suchas A is placed at or near the image planethen the light forming one of the superimposed images will fall .upon the screen with a predetermined inclination to the surface of the analyzer and Willbe broken up by the ribs of the analyzer and imaged by them as narrow stripes displaced to the'opposite side oi the optical axis of eachrib by an amount determined by the inclination of the incident light.

Since the inclination of the incident light is inherently difierent for each image, due to the diffferlng azimuths on deflector mirrors, Di D2, D3, Da it follows that the narrow stripes of images formed by the ribs of the analyzer A will be arranged side by side across the axis of the individual ribs and separated by an amount'predeter mined by the deflector azimuths. Once the superimposed images are analyzed into interlined banded images in this fashion they may be relayed on to the photographic surface by a relay lens, as at R, and

the resulting record will be c rectly on the photosensitive surface by placing the analyzer substantially in contact with the emulsion of film F but the relay form shown is preferred.

It is to be noted that this apparatus permits simultaneous recording of all of the station views and that there occur, therefore, no defects of image similarity due to motion in the object or other defects incident to the employment of moving parts.

The stereogram prepared as above described, may be viewed by projecting an image thereof onto a screen in register with a line screen in any well known manner. The stereogram of this invention may also be viewed in any other suit able manner,

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

l. A motion picture stereoscopic photographing arrangement comprising the combination of an arcuate array of a plurality of pairs of plane re-= flecting surfaces each adapted to form a reflected image ofan object irom a discrete viewpoint; said surfaces being symmetrically disposed about a base line symmetrical with regard to said base line and a lineater disposed in front of a light sensitive surface, said lineater receiving light rays reflected from said plane reflecting surfaces,

means symmetrical with respect to said base line for simultaneously divertingrays from a plurality of said plane reflecting surfaces to said lineater and to said light sensitive surface, and a.

relay lens between said lineater and said light sensitive surface.

2. Arrangement for forming a motion picture interllned parallax panoramagram of an object comprising more than two pairs of reflecting surfaces symmetrically arranged about a base line, one member of each of said pairs comprising a separate plane station mirror, each of said plane station mirrors adapted to form a reflected image of said object from a discrete viewpoint, the other member of each of said pairs receiving the image in its associated plane station mirror and simultaneously diverting the same along optical paths, with a lineater for a lightsensitive surface in said paths, and a relay lens between said lineater and the light sensitive surface said light sensitive surface being responsive to light of the same character for difierent angular viewpoints of said object.

ARTHUR W. CARPENTER. 

